Auto merge of #42146 - nrc:rls-rust, r=alexcrichton

More Rust/RLS integration

r? @alexcrichton

cc https://github.com/rust-lang-nursery/rls/issues/310

closes #41199
closes #41197

7 files changed, 134 insertions, 46 deletions

diff --git a/src/Cargo.lock b/src/Cargo.lock
index dae1aea3418..3c8d1164863 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -103,6 +103,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "bin_lib"
+version = "0.1.0"
+
+[[package]]
+name = "bin_lib_no_cfg_test"
+version = "0.1.0"
+
+[[package]]
 name = "bitflags"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -133,6 +141,10 @@ dependencies = [
 ]
 
 [[package]]
+name = "borrow_error"
+version = "0.1.0"
+
+[[package]]
 name = "bufstream"
 version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -155,7 +167,7 @@ dependencies = [
 [[package]]
 name = "cargo"
 version = "0.21.0"
-source = "git+https://github.com/rust-lang/cargo#1566c92b5d28e435613918e59dc94755f99d73b1"
+source = "git+https://github.com/rust-lang/cargo#5982cf904be1d72f575dcbd1e750c07bf730b966"
 replace = "cargo 0.21.0"
 
 [[package]]
@@ -191,8 +203,8 @@ dependencies = [
  "psapi-sys 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "scoped-tls 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "semver 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_ignored 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "shell-escape 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -218,7 +230,7 @@ dependencies = [
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "tar 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -290,6 +302,10 @@ dependencies = [
 ]
 
 [[package]]
+name = "completion"
+version = "0.1.0"
+
+[[package]]
 name = "core"
 version = "0.0.0"
 dependencies = [
@@ -302,8 +318,8 @@ version = "0.10.0"
 dependencies = [
  "curl 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -370,8 +386,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -427,6 +443,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "find_all_refs"
+version = "0.1.0"
+
+[[package]]
+name = "find_all_refs_no_cfg_test"
+version = "0.1.0"
+
+[[package]]
 name = "flate2"
 version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -494,6 +518,10 @@ version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "goto_def"
+version = "0.1.0"
+
+[[package]]
 name = "graphviz"
 version = "0.0.0"
 
@@ -516,7 +544,7 @@ dependencies = [
  "pest 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "quick-error 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -526,6 +554,14 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "highlight"
+version = "0.1.0"
+
+[[package]]
+name = "hover"
+version = "0.1.0"
+
+[[package]]
 name = "idna"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -579,8 +615,8 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "enum_primitive 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "url_serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -677,7 +713,7 @@ dependencies = [
  "open 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pulldown-cmark 0.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -719,6 +755,10 @@ dependencies = [
 ]
 
 [[package]]
+name = "multiple_bins"
+version = "0.1.0"
+
+[[package]]
 name = "net2"
 version = "0.2.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -958,6 +998,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "reformat"
+version = "0.1.0"
+
+[[package]]
+name = "reformat_with_range"
+version = "0.1.0"
+
+[[package]]
 name = "regex"
 version = "0.1.80"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1000,6 +1048,10 @@ name = "remote-test-server"
 version = "0.1.0"
 
 [[package]]
+name = "rename"
+version = "0.1.0"
+
+[[package]]
 name = "rls"
 version = "0.1.0"
 dependencies = [
@@ -1009,13 +1061,13 @@ dependencies = [
  "languageserver-types 0.11.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "racer 2.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "rls-analysis 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rls-analysis 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rls-data 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rls-span 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rls-vfs 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustfmt-nightly 0.1.8 (git+https://github.com/rust-lang-nursery/rustfmt?branch=rustfmt-42492)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustfmt-nightly 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1024,7 +1076,7 @@ dependencies = [
 
 [[package]]
 name = "rls-analysis"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "derive-new 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1049,8 +1101,8 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1463,8 +1515,8 @@ dependencies = [
 
 [[package]]
 name = "rustfmt-nightly"
-version = "0.1.8"
-source = "git+https://github.com/rust-lang-nursery/rustfmt?branch=rustfmt-42492#7333dfc95b4af5c7283ba03f33c50f108d2be3f5"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "diff 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1473,8 +1525,8 @@ dependencies = [
  "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "strings 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "term 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1503,7 +1555,7 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1513,12 +1565,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "serde"
-version = "1.0.9"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "serde_derive"
-version = "1.0.9"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1540,7 +1592,7 @@ name = "serde_ignored"
 version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1551,7 +1603,7 @@ dependencies = [
  "dtoa 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "itoa 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1837,7 +1889,7 @@ name = "toml"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1908,7 +1960,7 @@ name = "url_serde"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2082,19 +2134,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1731164734096285ec2a5ec7fea5248ae2f5485b3feeb0115af4fda2183b2d1b"
 "checksum regex-syntax 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f9ec002c35e86791825ed294b50008eea9ddfc8def4420124fbc6b08db834957"
 "checksum regex-syntax 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ad890a5eef7953f55427c50575c680c42841653abd2b028b68cd223d157f62db"
-"checksum rls-analysis 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "34c9957e6a7e336978f9262dff7552f80b6c8588483f221a8e63f5b436010862"
+"checksum rls-analysis 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ea940411ed2ad6d1e705fc2a0b146a0a3f30f8098ba4e61b45b4e5f2bfa7ed63"
 "checksum rls-data 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e502ac679bc35e023e982506c32d0278ef89e29af1e4ad21cb70c44b525b87a9"
 "checksum rls-span 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5d7c7046dc6a92f2ae02ed302746db4382e75131b9ce20ce967259f6b5867a6a"
 "checksum rls-vfs 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ffd34691a510938bb67fe0444fb363103c73ffb31c121d1e16bc92d8945ea8ff"
 "checksum rustc-demangle 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "3058a43ada2c2d0b92b3ae38007a2d0fa5e9db971be260e0171408a4ff471c95"
 "checksum rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)" = "dcf128d1287d2ea9d80910b5f1120d0b8eede3fbf1abe91c40d39ea7d51e6fda"
-"checksum rustfmt-nightly 0.1.8 (git+https://github.com/rust-lang-nursery/rustfmt?branch=rustfmt-42492)" = "<none>"
+"checksum rustfmt-nightly 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6693f90ac7d0a2291aa309f5214f5f3ac1bd79961c11116fcf6d5545749bf2e7"
 "checksum same-file 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d931a44fdaa43b8637009e7632a02adc4f2b2e0733c08caa4cf00e8da4a117a7"
 "checksum scoped-tls 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f417c22df063e9450888a7561788e9bd46d3bb3c1466435b4eccb903807f147d"
 "checksum semver 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3fdd61b85a0fa777f7fb7c454b9189b2941b110d1385ce84d7f76efdf1606a85"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
-"checksum serde 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6a7c6b751a2e8d5df57a5ff71b5b4fc8aaee9ee28ff1341d640dd130bb5f4f7a"
-"checksum serde_derive 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "2f6ca58905ebd3c3b285a8a6d4f3ac92b92c0d7951d5649b1bdd212549c06639"
+"checksum serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)" = "433d7d9f8530d5a939ad5e0e72a6243d2e42a24804f70bf592c679363dcacb2f"
+"checksum serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)" = "7b707cf0d4cab852084f573058def08879bb467fda89d99052485e7d00edd624"
 "checksum serde_derive_internals 0.15.1 (registry+https://github.com/rust-lang/crates.io-index)" = "37aee4e0da52d801acfbc0cc219eb1eda7142112339726e427926a6f6ee65d3a"
 "checksum serde_ignored 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c10e798e4405d7dcec3658989e35ee6706f730a9ed7c1184d5ebd84317e82f46"
 "checksum serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "48b04779552e92037212c3615370f6bd57a40ebba7f20e554ff9f55e41a69a7b"
diff --git a/src/Cargo.toml b/src/Cargo.toml
index 9cf6297d463..f027965e791 100644
--- a/src/Cargo.toml
+++ b/src/Cargo.toml
@@ -17,6 +17,20 @@ members = [
   "tools/rust-installer",
   "tools/cargo",
   "tools/rls",
+  # FIXME(https://github.com/rust-lang/cargo/issues/4089): move these to exclude
+  "tools/rls/test_data/borrow_error",
+  "tools/rls/test_data/completion",
+  "tools/rls/test_data/find_all_refs",
+  "tools/rls/test_data/find_all_refs_no_cfg_test",
+  "tools/rls/test_data/goto_def",
+  "tools/rls/test_data/highlight",
+  "tools/rls/test_data/hover",
+  "tools/rls/test_data/rename",
+  "tools/rls/test_data/reformat",
+  "tools/rls/test_data/bin_lib_no_cfg_test",
+  "tools/rls/test_data/multiple_bins",
+  "tools/rls/test_data/bin_lib",
+  "tools/rls/test_data/reformat_with_range",
 ]
 
 # Curiously, compiletest will segfault if compiled with opt-level=3 on 64-bit
diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index 371512908a0..e4b0e2fb9ca 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -15,6 +15,7 @@
 
 use std::collections::HashSet;
 use std::env;
+use std::ffi::OsString;
 use std::iter;
 use std::fmt;
 use std::fs::{self, File};
@@ -117,14 +118,7 @@ pub fn cargotest(build: &Build, stage: u32, host: &str) {
 
 /// Runs `cargo test` for `cargo` packaged with Rust.
 pub fn cargo(build: &Build, stage: u32, host: &str) {
-    let ref compiler = Compiler::new(stage, host);
-
-    // Configure PATH to find the right rustc. NB. we have to use PATH
-    // and not RUSTC because the Cargo test suite has tests that will
-    // fail if rustc is not spelled `rustc`.
-    let path = build.sysroot(compiler).join("bin");
-    let old_path = env::var_os("PATH").unwrap_or_default();
-    let newpath = env::join_paths(iter::once(path).chain(env::split_paths(&old_path))).expect("");
+    let compiler = &Compiler::new(stage, host);
 
     let mut cargo = build.cargo(compiler, Mode::Tool, host, "test");
     cargo.arg("--manifest-path").arg(build.src.join("src/tools/cargo/Cargo.toml"));
@@ -139,7 +133,31 @@ pub fn cargo(build: &Build, stage: u32, host: &str) {
     // available.
     cargo.env("CFG_DISABLE_CROSS_TESTS", "1");
 
-    try_run(build, cargo.env("PATH", newpath));
+    try_run(build, cargo.env("PATH", &path_for_cargo(build, compiler)));
+}
+
+/// Runs `cargo test` for the rls.
+pub fn rls(build: &Build, stage: u32, host: &str) {
+    let compiler = &Compiler::new(stage, host);
+
+    let mut cargo = build.cargo(compiler, Mode::Tool, host, "test");
+    cargo.arg("--manifest-path").arg(build.src.join("src/tools/rls/Cargo.toml"));
+
+    // Don't build tests dynamically, just a pain to work with
+    cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");
+
+    build.add_rustc_lib_path(compiler, &mut cargo);
+
+    try_run(build, &mut cargo);
+}
+
+fn path_for_cargo(build: &Build, compiler: &Compiler) -> OsString {
+    // Configure PATH to find the right rustc. NB. we have to use PATH
+    // and not RUSTC because the Cargo test suite has tests that will
+    // fail if rustc is not spelled `rustc`.
+    let path = build.sysroot(compiler).join("bin");
+    let old_path = env::var_os("PATH").unwrap_or_default();
+    env::join_paths(iter::once(path).chain(env::split_paths(&old_path))).expect("")
 }
 
 /// Runs the `tidy` tool as compiled in `stage` by the `host` compiler.
diff --git a/src/bootstrap/mk/Makefile.in b/src/bootstrap/mk/Makefile.in
index 47c792a510b..ad0ee8d47d6 100644
--- a/src/bootstrap/mk/Makefile.in
+++ b/src/bootstrap/mk/Makefile.in
@@ -55,7 +55,8 @@ check:
 check-aux:
 	$(Q)$(BOOTSTRAP) test \
 		src/tools/cargotest \
-		cargo \
+		src/tools/cargo \
+		src/tools/rls \
 		src/test/pretty \
 		src/test/run-pass/pretty \
 		src/test/run-fail/pretty \
diff --git a/src/bootstrap/step.rs b/src/bootstrap/step.rs
index 5a1ef818ccf..a1b26f44b7d 100644
--- a/src/bootstrap/step.rs
+++ b/src/bootstrap/step.rs
@@ -472,10 +472,14 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
          .dep(|s| s.name("librustc"))
          .host(true)
          .run(move |s| check::cargotest(build, s.stage, s.target));
-    rules.test("check-cargo", "cargo")
+    rules.test("check-cargo", "src/tools/cargo")
          .dep(|s| s.name("tool-cargo"))
          .host(true)
          .run(move |s| check::cargo(build, s.stage, s.target));
+    rules.test("check-rls", "src/tools/rls")
+         .dep(|s| s.name("tool-rls"))
+         .host(true)
+         .run(move |s| check::rls(build, s.stage, s.target));
     rules.test("check-tidy", "src/tools/tidy")
          .dep(|s| s.name("tool-tidy").stage(0))
          .default(true)
diff --git a/src/tools/rls b/src/tools/rls
-Subproject 70b89fdd7e5e77a3b88fc68982861d39d155be2
+Subproject 618f802f0dcebc9f23a527afd3cd228c1fa468f
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index ba02ee0c6d7..8b7da2267cd 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -32,7 +32,6 @@ static EXCEPTIONS: &'static [&'static str] = &[
     "openssl", // BSD+advertising clause, cargo, mdbook
     "pest", // MPL2, mdbook via handlebars
     "thread-id", // Apache-2.0, mdbook
-    "strings", // this is actually MIT/Apache-2.0 but it's not in the manifest yet
 ];
 
 pub fn check(path: &Path, bad: &mut bool) {